Conventionally, a magnetic tape cartridge (recording medium cartridge) is provided with a cartridge memory other than a magnetic tape, which is a recording medium, for recording information such as a manufacturing number and usage history unique to the magnetic tape cartridge. Because such the cartridge memory can send/receive electric power and signals with no contact, it is housed in a cartridge case of the magnetic tape cartridge (for example, see page 2 and FIGS. 7 and 8 in Japan patent laid open publication 2001-332064).
Meantime, because a conventional magnetic tape cartridge is set so that recording/reproducing and modifying data can be repeated, so it is difficult to simply verify data authentication (whether or not the data is tampered). Especially, in fields of medical care, law, and the like, assuring data authentication recorded in a magnetic tape cartridge is required, so it is needed to simply assure the data authentication.